Answer:
option E
Explanation:
the correct answer is option E
the direction of magnetic field will be found out with the help of right hand rule.
Put you palm in the direction of electric field and curl your finger in the direction of magnetic field which east direction.
now, the direction shown by the thumb will be the direction of magnetic field which comes out to be toward South direction.
Explanation:
Given that,
The mean kinetic energy of the emitted electron, 
(a) The relation between the kinetic energy and the De Broglie wavelength is given by :



(b) According to Bragg's law,

n = 1
For nickel, 



As the angle made is very small, so such an electron is not useful in a Davisson-Germer type scattering experiment.
Answer:
B) Power is the rate at which work is done